1. Field of the Invention
The present invention relates to pivot valves and more particularly to replaceable seal rings for said valves.
2. Description of the Prior Art
Heretofore, butterfly and ball valves have not been available with conveniently replaceable seal rings that meet all of the required operating characteristics for high performance butterfly and ball valves. The seal rings for these pivot type valves have been retained by many and varied means. The most common method of retaining a seal ring in a valve body is to bond the seal ring in an annular groove; however, the bonding made replacement of the seal ring an extremely laborious operation because of the difficulty encountered in removing all of the bonded seal ring from the annular groove. Replaceable seal rings have been provided using various forms of rigid or flexible retaining rings or threaded fasteners; however, these devices proved to be expensive and inconvenient. In some devices, the valve body itself was divided into two parts that would engage and retain the seal ring when connected.